diff --git a/core/katvan_completionmanager.cpp b/core/katvan_completionmanager.cpp
index c923c3d..0d89593 100644
--- a/core/katvan_completionmanager.cpp
+++ b/core/katvan_completionmanager.cpp
@@ -174,7 +174,6 @@ QSize CompletionSuggestionDelegate::sizeHint(const QStyleOptionViewItem& option,
 {
     QString label = index.data(Qt::DisplayRole).toString();
     QString detail = index.data(COMPLETION_DETAIL_ROLE).toString();
-    QIcon icon = qvariant_cast<QIcon>(index.data(Qt::DecorationRole));
 
     QFontMetrics labelMetrics { d_labelFont };
     QFontMetrics detailMetrics = option.fontMetrics;
@@ -182,7 +181,8 @@ QSize CompletionSuggestionDelegate::sizeHint(const QStyleOptionViewItem& option,
     int width = labelMetrics.horizontalAdvance(label);
     int height = labelMetrics.height();
 
-    for (QString line : detail.split(QChar::LineFeed)) {
+    const QStringList lines = detail.split(QChar::LineFeed);
+    for (const QString& line : lines) {
         width = qMax(width, detailMetrics.horizontalAdvance(line));
         height += detailMetrics.height();
     }
@@ -239,8 +239,10 @@ void CompletionManager::completionsReady(int line, int column, QByteArray comple
         return;
     }
 
+    const QJsonArray completionsArray = doc.array();
+
     QList<QJsonObject> suggestions;
-    for (const QJsonValue& value : doc.array()) {
+    for (const QJsonValue& value : completionsArray) {
         suggestions.append(value.toObject());
     }
     d_model->setSuggestions(suggestions);
diff --git a/core/katvan_diagnosticsmodel.cpp b/core/katvan_diagnosticsmodel.cpp
index e56de72..cd8fe0b 100644
--- a/core/katvan_diagnosticsmodel.cpp
+++ b/core/katvan_diagnosticsmodel.cpp
@@ -148,7 +148,8 @@ QVariant DiagnosticsModel::data(const QModelIndex& index, int role) const
     }
     else if (index.column() == COLUMN_MESSAGE && (role == Qt::DisplayRole || role == Qt::ToolTipRole)) {
         QString message = diagnostic.message();
-        for (const QString& hint : diagnostic.hints()) {
+        QStringList hints = diagnostic.hints();
+        for (const QString& hint : std::as_const(hints)) {
             message += QChar::LineFeed + QStringLiteral("Hint: ") + hint;
         }
         return message;
diff --git a/core/katvan_document.h b/core/katvan_document.h
index 2b9f884..f4bf6ab 100644
--- a/core/katvan_document.h
+++ b/core/katvan_document.h
@@ -39,8 +39,8 @@ enum class BlockDataKind
 
 template <typename T>
 concept BlockDataSection = requires {
-    std::derived_from<T, QTextBlockUserData>;
-    std::same_as<decltype(T::DATA_KIND), BlockDataKind>;
+    requires std::derived_from<T, QTextBlockUserData>;
+    requires std::same_as<decltype(T::DATA_KIND), const BlockDataKind>;
 };
 
 class BlockData : public QTextBlockUserData
diff --git a/core/katvan_previewerview.cpp b/core/katvan_previewerview.cpp
index 69c5546..5b81dbe 100644
--- a/core/katvan_previewerview.cpp
+++ b/core/katvan_previewerview.cpp
@@ -127,7 +127,7 @@ void PreviewerView::setPages(QList<typstdriver::PreviewPageData> pages)
     else if (hadPages) {
         // In case of new content in an already open preview - invalidate
         // only pages that have actually changed
-        QList<int> keys = d_renderCache.keys();
+        const QList<int> keys = d_renderCache.keys();
         for (int key : keys) {
             if (key >= pages.size()) {
                 d_renderCache.remove(key);
@@ -368,7 +368,8 @@ void PreviewerView::scrollerStateChanged()
 
 void PreviewerView::invalidateAllRenderCache()
 {
-    for (int page : d_renderCache.keys()) {
+    const QList<int> pages = d_renderCache.keys();
+    for (int page : pages) {
         d_renderCache.object(page)->invalidated = true;
     }
     viewport()->update();
diff --git a/core/katvan_spellchecker_hunspell.cpp b/core/katvan_spellchecker_hunspell.cpp
index b72e5ea..82f32b5 100644
--- a/core/katvan_spellchecker_hunspell.cpp
+++ b/core/katvan_spellchecker_hunspell.cpp
@@ -319,7 +319,8 @@ void HunspellSpellChecker::setPersonalDictionaryPath()
 
     loadPersonalDictionary();
 
-    for (const QString& file : d_watcher->files()) {
+    const QStringList watchedFiles = d_watcher->files();
+    for (const QString& file : watchedFiles) {
         d_watcher->removePath(file);
     }
     d_watcher->addPath(d_personalDictionaryPath);
diff --git a/core/katvan_typstdriverwrapper.cpp b/core/katvan_typstdriverwrapper.cpp
index 87ea06e..88fea26 100644
--- a/core/katvan_typstdriverwrapper.cpp
+++ b/core/katvan_typstdriverwrapper.cpp
@@ -94,7 +94,7 @@ void TypstDriverWrapper::resetInputFile(const QString& sourceFileName)
             hasPending = true;
         }
         if (!d_pendingEdits.isEmpty()) {
-            for (const auto& edit : d_pendingEdits) {
+            for (const auto& edit : std::as_const(d_pendingEdits)) {
                 applyContentEdit(edit.from, edit.to, edit.text);
             }